Process for dyeing pelts, hairs, feathers, and the like.



STATES FATE FRANZ MERKEL, OF OFFENB ACH-ON-THE-MAIN, GERMANY, ASSIGNOR TO CORPORA- TION' OF CHEMISCHE FABRIK GRIESHEIM-ELEKTRON, OF FRANKFORT-ON-THE-- MAIN, GERMANY.

Be it known that I, FRANZ MERKEL, a citizen of the German Empire, and resident of Ofienbach-on-the-Main, in the Grand Duchy of Hesse, Germany, with the post-ofiice ad dress Landgrafenring 7, have invented new and useful Improvements in Processes for Dyeing Pelts, Hairs, Feathers, and the like, of which the following is a specification.

I have found, that by means of meta-oxydiphenylamin valuable brown dyeings are obtained on pelts, hairs, feathers and the like by treating the pelts, etc., mordanted or not, with a solution of meta-oxydiphenylamin, adding an oxidizing agent. The thus obtained dyeings possess a great fastness to 7 light and differ from those dyeings'hitherto obtained on the mentioned materials, by not having the reddish tinge of those dyeings.

Moreover they have the characteristics of natural skins, and therefore are valuable foi' the production of imitations of natural pe ts.

The following example illustrates the invention: Raw skin or skins prepared in the usual way, for example, by washing, followed by treating the ends of the hair with alkalis, are introduced for about 6 hours into a mordant, consisting of a solution of 3 grams of bichromate of sodium and 2 grams of sulfate of copper per liter. Sub-. sequently the skins are introduced into the real dye-bath consisting of: for instance1.5 to 3 grams of meta-oxydiphenylamin, 1.25 to 2.50 c. c. m. caustic soda lve (28 per cent), 1 liter of water. Immediately about 25 c. c. m. of bichromate-solution (1:10} are added, and then about 1 to 2 grams of perborate of sodium. In the so produced liquid the skins are at first well handled and'after' Specification of Letters Patent;

Patented Mar. 1a, 1916.

Application filed April 22, 1915. Serial No. 23,075.

about half an hour, about 5 c. c. m. of formic acid (1:10) are added, the skins being well handled meanwhile untilthe liquid does not prove alkaline any more by testing on testpaper, but shows a nearly neutral or only a little acid reaction. The skins are kept in the liquid referred to for a considerable time, for example during an entire night, and are handled from time to time; they are then taken out, washed well, centrifuged and finished in the usual manner. A beautiful deep brown of a very good fastness to light is obtained.

In the place of a solution of bichromate andperborate of sodium there can be used other oxidizing agents for instance a solution of hydrogen peroxid.

In the same manner hairs, feathers and the like can be dyed.

Now what I claim and desire to secure by Letters Patentis the following:

1: Process for dyeing pelts, hairs,-feathers and the like which comprises treating the material to be dyed in a solution of metaoxydiphenylamin containing an oxidizing agent.

2. Process for dyeing mordanted pelts, hairs, feathers and the like which comprises treating the mordanted material to be dyed in a solution of meta-oxydiphenylam in containing an oxidizing agent, substantlally as described.

That I claim the foregoing as my invention, I have signed my'name in presence of FRANZ MERKEL.

Witnesses:

JEAN GRUND, CARL GRUND. 

